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Are you awake during a colonoscopy procedure?

A colonoscopy is a common medical procedure used to examine the inside of the large intestine (colon and rectum) for abnormalities or disease. During a colonoscopy, a long, flexible tube called a colonoscope is inserted into the rectum and guided through the entire colon. The colonoscope has a camera and light at the tip which allows the doctor to view the lining of the colon on a monitor. Many patients wonder if they are awake during this procedure or if some kind of sedation is used.

Are you fully awake during a colonoscopy?

In most cases, patients are not fully awake and alert during a colonoscopy. Instead, the procedure is performed under sedation using medication to make you relaxed and comfortable. There are a few different options for sedation:

  • Conscious sedation – Also known as “twilight anesthesia.” This uses medication given through an IV line to induce relaxation and drowsiness. You may drift off to sleep during parts of the procedure but can still respond to touch and commands. Medications like midazolam, fentanyl, and propofol are commonly used.
  • Deep sedation – This induces an unconscious, deep sleep-like state. You are not easily roused and may not remember the procedure afterward. Anesthesia medications like propofol or sevoflurane are used to achieve deep sedation.
  • General anesthesia – This causes total unconsciousness as if in a deep sleep. Medications like propofol or sevoflurane are used. General anesthesia requires monitoring by an anesthesia professional.

In most routine colonoscopy cases, conscious sedation is sufficient for patient comfort. The medications cause drowsiness and relaxation but still allow you to respond to instructions during the procedure if needed. The level of sedation can be adjusted based on your needs and preferences.

Why use sedation for colonoscopies?

There are several reasons sedation is commonly used for colonoscopies:

  • The colonoscope tube can cause cramping or discomfort when inserted and maneuvered around colon turns and bends. Sedation helps patients relax through any pain or distress.
  • Some people feel anxious or embarrassed about the procedure. Sedation provides relaxation and eases anxiety.
  • Sedation allows the gastroenterologist to thoroughly examine the colon lining. If awake, the natural reflex would be to push out the colonoscope, limiting the exam.
  • Medication provides amnesia, so most patients do not remember the procedure afterwards.
  • Sedation allows patients to lie comfortably without having to actively participate or respond during the typically 20-60 minute colonoscopy.

Are there colonoscopies without sedation?

It is possible to have a colonoscopy performed without any sedation, also known as an unsedated colonoscopy. This may be offered in limited cases such as:

  • Patients at high risk of sedation complications due to health conditions like severe lung disease, sleep apnea, or heart failure.
  • Patients with adverse medication reactions or allergies to standard sedatives used.
  • Cases where driving immediately after the procedure is needed.

Unsedated colonoscopies are more likely to cause discomfort and require relaxation techniques by the patient. The procedure may also need to be limited or stopped early if too difficult to tolerate. Sedation is still preferred in most colonoscopies when appropriate for the patient.

What happens right before a colonoscopy under sedation?

Here are typical steps right before starting a colonoscopy with sedation:

  1. An IV line will be inserted into your arm/hand vein.
  2. Vital signs like blood pressure, pulse, oxygen saturation will be monitored.
  3. You will lie on your left side with knees bent.
  4. Sedative medications will be administered through the IV.
  5. Once suitably relaxed and drowsy, the colonoscope will be inserted via the rectum.
  6. More sedation medication can be given during the procedure as needed for comfort.

The sedation medications generally kick in quickly, within about 30-60 seconds after injection. You will feel very relaxed, sleepy, and comfortable. The gastroenterologist may speak to you during the procedure to check your level of sedation.

What do you experience during the procedure under sedation?

Under light-moderate conscious sedation, you may experience:

  • A sensation of the colonoscope tube moving inside.
  • Feeling like you need to move your bowels.
  • Cramping or discomfort at times when the tube maneuvers difficult colon turns.
  • Awareness of being examined but feeling detached from the procedure.
  • Brief periods of wakefulness interspersed with sleep.
  • The doctor speaking to you and giving commands to turn onto your back or side.

Under deep sedation or general anesthesia, you are unlikely to experience any awareness or recollection of the procedure afterward.

What happens after the colonoscopy once the sedation wears off?

After the colonoscopy examination is finished, the colonoscope is gently removed from the rectum. You will be monitored in a recovery area until the sedation wears off. This typically takes 1-2 hours but can be longer depending on your response. You may temporarily experience:

  • Drowsiness, sleepiness
  • Lightheadedness
  • Headache
  • Sore throat from the endoscopy tube
  • Bloating and gas due to air inserted into the colon during the procedure.
  • Forgetfulness or lack of recall about the procedure.

You will need someone to drive you home after you are discharged since the sedation can impair reflexes and judgement for the rest of the day. The sedative medications are eliminated from the body within 24 hours. You can discuss the complete colonoscopy results at a follow up appointment with your doctor later.

What are the risks of sedation during colonoscopy?

Sedation does carry minor risks, although complications are rare in healthy individuals:

  • Breathing problems – Sedatives may slow breathing rate. Oxygen saturation is monitored and supplemental oxygen is given if levels fall.
  • Blood pressure changes – Blood pressure may drop after sedation but generally returns to normal once the colonoscopy is finished.
  • Arrhythmias – Irregular heart rhythms may rarely occur after sedative injection.
  • Allergic reaction – Allergies to sedatives can cause rash, itching, or anaphylaxis in susceptible patients.

Make sure your doctor knows if you have any allergies or prior issues with sedation. In most cases, sedation is very safe with a low risk of complications when administered by trained professionals.

Who should not have sedation during colonoscopy?

The following groups may not be good candidates for sedation with colonoscopy:

  • Patients at high risk for breathing issues, like those with advanced COPD or sleep apnea.
  • Individuals with severely low blood pressure or unstable heart function.
  • People with allergies to standard colonoscopy sedative medications.
  • Those unable to lie still for an extended time due to chronic pain, mobility issues, or anxiety.
  • Patients with cognitive impairment who may be unable to follow directions during the procedure due to sedation.

Talk to your doctor about whether sedation or unsedated colonoscopy is preferable based on your health status.

Is it possible to wake up during colonoscopy due to light sedation?

It is possible to have brief moments of waking up if you are under relatively light conscious sedation during the procedure. This may happen if:

  • Not enough sedative medication was given initially.
  • The sedation is starting to wear off towards the end of a longer colonoscopy.
  • A particularly painful area like an acute diverticulitis causes you to rouse temporarily.
  • Loud noises or discomfort arise.

If you do start to wake up and feel pain, your doctor can quickly give more sedation through the IV to make you comfortable again. Maintaining adequate sedation levels throughout the colonoscopy is the anesthesiologist’s role.

Will I be able to watch the colonoscopy on the monitor?

You will not purposefully be able to watch the colonoscopy images on the screen since you are under sedation. However, some patients report they were able to watch briefly if their sedation level was lighter. The monitor is positioned near the doctor performing the procedure, so you may get quick glimpses.

Many gastroenterologists will intentionally turn the monitor away from the patient’s line of sight to avoid any chance of seeing the procedure while under light sedation. There is black drape that obscures the bottom half of your body from view as well. Trying to view the colonoscopy typically is not recommended since it may cause discomfort or anxiety in an awake patient.


Overall, sedation is considered safe, effective, and well-tolerated for most patients undergoing colonoscopies. Being sedated provides comfort, amnesia, and optimal conditions for the physician to thoroughly examine the colon. While brief awakening is possible under lighter sedation, the anesthesiologist will monitor you closely and adjust medication as needed. Talk to your doctor if you have any concerns about sedation options before your colonoscopy.